Abstract:As one of the morphing methods, wing camber morphing technology has received great attention. First the relevant projects of camber morphing are analyzed and summarized. And then focusing on the aeroelastic modeling and analysis means of the camber morphing technology, aeroelastic stability, aeroelastic optimization and control are conducted and analyzed. Different research means are evaluated and the technical difficulties currently facing are analyzed. The problems to be solved are pointed out in order to provide guidance for the further improvement of the camber morphing technology.

Abstract:The aerodynamic configuration of supersonic aircraft has an important effect on the intensity of sonic boom. Low sonic boom supersonic aircraft aerodynamic configurations have been researched extensively. Based on the systematic investigation of foreign sonic boom suppression technologies, this paper describes five aerodynamic methods proposed by foreign researchers for reducing sonic boom of supersonic aircraft, and sums up relevant lessons and experience. Four main aerodynamic configuration types of low boom supersonic aircraft are summarized and analyzed. According to the aerodynamic configurations of new supersonic aircraft, it is concluded that the delta wing is the mainstream aerodynamic configuration of the next generation environmentally friendly aircraft. An outlook of the aerodynamic configurations of low boom supersonic aircraft is given in the last part. .

Abstract:The flush air data sensing system is a key or important flight sensor subsystem for the measurement of flight atmospheric parameters such as air pressure altitude,indicated airspeed,Mach number,Angle of attack and sideshow Angle, which are required for flight safety control,communication and navigation of flying wing pneumatic layout aircraft and precise weapon strike. The effectiveness of water-proof, dust-proof, anti-ice and de-icing design of the flush air data pressure sensor in the system is an important guarantee for accurate pressure feeling, stability of atmospheric parameters and real-time performance during flight. In this paper, aiming at the technology present status of waterproof, dustproof, anti-icing and de-icing of flush air data pressure sensors in flush air data system, analyzed the existing shortcomings and defects, combined with the needs of engineering application and research results of related engineering technology, proposed flush air data pressure sensor complex meteorological environment protection status online monitoring, heater power adaptive control and rapid disassembling design as development direction, illuminates the future of flush air data pressure sensor complex meteorological environment protection technology research goal, content, and involves water, the solutions of key technologies such as moisture monitoring technology, freezing condition monitoring technology, Surface hydrophobic and low detectable technology and easy maintenance structure design technology are given.

Abstract:One of the key problems to improve the aerodynamic characteristics of airfoil is to solve the dynamic stall. This paper presents a method to control the dynamic stall of airfoil by using the combination of leading edge suction and trailing edge suction. The influence and control effect of pitch oscillation on the dynamic stall characteristics of airfoil are investigated. Taking NACA0012 airfoil as the research object, the unsteady Reynolds-averaged Navier-Stokes equation is solved based on the Transition SST turbulence model, and the aerodynamic characteristics of airfoil with different jet momentum coefficients are calculated. It is found that under the conditions of Mach number 0.109, reduction frequency 0.1, average angle of attack 14.84° and amplitude 9.89°, When the jet dynamic coefficient is 0.0065, compared with the control without blowing and suction, the airfoil has no obvious stall phenomenon, the average lift coefficient increases by 59%, the average drag coefficient decreases by 40%, and the negative pitching moment peak is eliminated, which indicates that the combined blowing and inhaling flow control can improve the dynamic characteristics of the airfoil and play a certain role in suppressing the dynamic stall of the airfoil.

Abstract:The variant aircraft can change its shape to adapt to different flight states and improve flight performance. Its design includes various disciplines such as aerodynamics, materials and structures. The research focuses on a new hypersonic vehicle concept machine. The applicability of the wing variable sweep design on this hypersonic aircraft is discussed, and the influence of the deformation design of directly extending the trailing edge of the wing on the aerodynamics of the aircraft is studied. First, obtained the 3D model of the hypersonic vehicle with different deformable wings. Then, based on the k-ε turbulence model in FLUENT, the numerical simulation of the external flow field around the hypersonic vehicle was carried out respectively. Finally, the aerodynamic characteristics of the hypersonic vehicle under different angles of attack and different wing deformation schemes were analyzed. The research results show that the variable-sweep wing scheme cannot achieve the goal of improving the lift-to-drag ratio under the design conditions of the hypersonic vehicle, and the deformation design of directly extending the wing can improve the aerodynamic characteristics of the hypersonic vehicle under the design conditions. The research results can provide reference for the design of hypersonic variant aircraft, and have certain practical value.

Abstract:The tilt-rotor unmanned aerial vehicles have an obvious trend of multi-rotor development, and modular design of tiltable rotor system helps to integrate assembly and reduce design duplication. In this paper, a quad tilt-rotor unmanned aerial vehicle (UAV) is targeted, and the modular design concept is applied to the design of the tiltable rotor system. Firstly, the modular mechanical structure, control structure and communication structure of the tiltable rotor system are designed. By using CAN bus communication mechanism designed, the tiltable rotor system is connected to the overall distributed control system as a node. Then, the internal pitch control, rotor speed control and rotor tilting control of the tiltable rotor system are studied. Finally, a tiltable rotor system test platform is built to verify the correctness of each component design of the tiltable rotor system modular components and the feasibility of the modular design concept. The results show that the rotor speed fluctuation error is less than 2.6%, the smooth and uniform transition from helicopter mode to fixed wing mode can be achieved within 7s, and the system has good real-time data communication, which meet the application requirements of tiltable rotor system. The modular design of tiltable rotor system can provide technical means and ways for the development of quad tilt-rotor UAV.

Abstract:In order to obtain an accurate structural dynamics model, this paper adopts a model update method that integrates the Kriging model and the MOGA algorithm for the GARTEUR aircraft to verify the feasibility of using a fusion of the Kriging model and the MOGA algorithm in the dynamics model correction. The initial parameters of the aircraft model were first screened using Spearman correlation analysis and the introduction of a significance level coefficient P. The screened parameters were then used as design variables to obtain the initial sample points using the OSF experimental design method, construct the Kriging response surface model, use the difference between the response surface calculation results and the experimental results as the objective function, and finally the MOGA algorithm is used to optimize the objective function, search for the Pareto optimal solution and add validation points to the candidate points to check its accuracy. The results show that the updated GARTEUR aircraft model has good frequency reproduction and prediction capability, and meets the engineering accuracy requirements, proving the effectiveness and reliability of using the fused Kriging model and MOGA algorithm in the dynamics model revision.

Abstract:With the fourth generation stealth aircraft gradually becoming the main combat equipment of major military powers in the world, the improvement of missile anti stealth combat capability has become an inevitable requirement for the construction of weapons and equipment. In the evaluation of missile operational effectiveness, real shot shooting is an essential link. At present, there are a certain number of small stealth target aircraft that can be used to simulate the main target characteristics of the fourth generation stealth aircraft. However, their analysis of simulation fidelity and the accuracy of missile operational effectiveness evaluation is rarely seen in relevant literature. This paper makes a detailed comparison and analysis of the differences between the small stealth target and the real stealth aircraft in radar scattering characteristics, physical dimensions, vulnerability, electronic countermeasure characteristics, etc. Through the study of the impact of the differences in target characteristics on missile functions and effectiveness, it is believed that the small stealth target is difficult to be comprehensive To accurately evaluate the operational effectiveness of missiles.due to its own shape and size inherent characteristics, it is necessary to attach importance to the development of large-scale stealth target aircraft, which is of positive significance for evaluating the operational effectiveness of missiles and correctly guiding the improvement of missile anti stealth capability.

Abstract:The deflecting to airflow flap of civil aircraft are generally driven by complex multi-hinge mechanisms in space. According to the requirements of airworthiness clause CCAR25.671, it is necessary to carry out research on mechanism characteristics under typical faults.Firstly, a digital prototype of complex multi-hinge space mechanism is constructed. The multi-point constraint RBE3 element is used to associate the intersection point of the rigid multi-hinge mechanism to the flexible flap body, and the rigid-flexible coupling dynamic model of the flap mechanism is established.Under the three aerodynamic load conditions of cruise, take-off and landing, two typical faults, hinge jamming and single-point failure of the control system, were simulated by adjusting the friction coefficient of the hinge kinematic pair and setting the single-side drive failure.Finally, the variation law of flap driving moment and hinge point load under fault conditions is analyzed. The results show that: when the hinge is jamming,the torque of the inner mechanism will reach 1.57×108 N·mm in 0.8s, and the inner driving link ear piece will be stretched and damaged. When the inner mechanism fails, the driving torque of the outer mechanism increases by 7.5 times, and the maximum radial load of the rocker arm hinge point increases by a maximum of 13.5 times.In practice, we should focus on the radial bearing capacity of the joint bearing in the outer rocker arm of this type of flap to avoid the situation of independent manipulation of the outer mechanism, and at the same time, it is necessary to add torque protection to the entire drive system.

Abstract:The door and frame of civil aircraft transfer loads through face-to-face contact between interface parts, while the interface clearance affects the load distribution, thus it’s quite crucial for flight safety. However, there is a lack of interface clearance and its influence on load distribution in existing studies, and also design method of interface clearance in engineering. In this paper, a design method of interface clearance is proposed, which essentially is a Monte Carlo simulation based on clearance randomness. A detailed finite element model of both door and frame is established, in which the linear gap and the Direct Matrix Input Grid are introduced, the load distribution affected by the clearance randomness is analyzed. In simulation, design basis and mathematical describing method of the interface clearance are determined, and finally design boundaries with 95% reliability are given. The method provides a theoretical foundation for the interface clearance design.

Abstract:At present, the application of semi-active control technology on landing gear is mostly limited to single landing gear or magnetorheological landing gear. The research on the whole aircraft is more valuable for the practical application of semi-active control. In this paper, LMS Virtual.lab Motion multi-body dynamics software is used to establish a virtual model of the aircraft. Taking the single-chamber oil and gas buffer as the research object, the mechanical models of passive control and semi-active control are analyzed, and the oil and gas buffer is built in AMESim. Based on the fuzzy control theory and variable damping throttle semi-active control principle, a fuzzy controller is designed in MATLAB/Simulink, and the controller model is integrated into AMESim to realize real-time control of the orifice. Finally, through the 3D-1D co-simulation of mechanical, hydraulic and control, the simulation results of the aircraft under passive control and semi-active control are analyzed. The semi-active control of fuzzy PID responds quickly, and the peak vertical load of the buffer struts is reduced by 20.5% and 13.1% respectively, and the buffering efficiency is also higher than that of passive control; at the same time, the peak vertical acceleration of the fuselage is reduced by 23.2%, and the vibration is stabilized faster, which improves the Ride comfort.

Abstract:With the large-scale application of composite materials in aircraft structures, the threat of visually invisible damage such as internal delamination of composite materials caused by impact from foreign objects is increasing，therefore, impact event monitoring and impact location identification of composite reinforced structures is essential. In order to verify the engineering validity of the impact localization algorithm, based on the piezoelectric sensing signal of the impact test on the composite large wall plate structure, the localization accuracy of the time-reversal focusing，error function and cross-correlation function impact monitoring algorithms is compared. The results show that, In the monitoring area of 2360mm×1260mm, the error of the cross-correlation function algorithm is smaller than that of the time-reversal focusing algorithm, and the error of the time-reversal focusing algorithm is larger at the truss, which is not suitable for impact positioning of reinforced structures.

Abstract:The technical status data for in-service aircraft plays an important role in aircraft operation and support. For satisfying the requirements of Full Life Cycle Support for military aircraft，it’s necessary to manage the technical status data. At present, due to lack of the domestic technical status data management standards for in-service aircraft,, , the data management between the different stakeholders is not planed as a whole, the data is difficult to synchronize, correlate and trace, the utilization of data is very difficult, so it can’t ensure efficiency and quality of aircraft logistics. S5000F(International specification for in-service data and feedback) provides a guide for the in-service data management. In view of aircraft designer, , the research constructs a framework of the in-service data management for aircraft through interpreting the in-service data management of S5000F，. Also., the research builds a a dynamic traceable tool of in service data management based on UML data model .The results show that the research is feasible after being applied to aircraft logistics，which can ensure Full Life Cycle Support for military aircraft.

Abstract:As there exist a variety of factors influencing aeroengine maintenance quality and cost, very few research focuses on maintenance optimization under specific scenarios of aeroengine maintenance enterprises. In order to clarify the relationship between the factors affecting aeroengine maintenance and meet the demandings of enterprises, maintenance, repair and operation (MRO) process is systematically modeled in this research, which mainly includes five parts: main body of procedure, flight time statistics, human resources, performance evaluation and maintenance cost. Two practical application scenarios of enterprise including human resource quality control and performance oriented were investigated by using the principle of system dynamics and grey wolf optimizer assisted by Vensim, MATLAB and other analysis software, which reveals the importance of human resource quality, employee satisfaction and planned maintenance. In consideration of the actual impact of various factors on aeroengine maintenance, the results show that the proposed modeling and optimization method is feasible and effective.

Abstract:Pilots and controllers are the key roles in the air traffic control system, and the evolution of the control system can be obtained by analyzing the relationship between them. The control-aircraft state interdependence network is constructed according to the aircraft flight conflict, the handover relationship between control sectors and the command and monitoring of aircraft. By counting the characteristics of nodes in the evolution process of the interdependence network, the changes of controller workload and aircraft flight conflict during the evolution process are analyzed. Then, the maximum Lyapunov exponent and phase diagram analysis are used to identify the chaos of the system. The results show that the characteristics of control sector and aircraft node can reflect the changing trend of control system. The evolution law of control system is chaotic and predictable.

Abstract:Airborne system is developing towards the direction of integration, intelligence and automation. The integration of the system is usually realized by the way of cross-linking of the system. The cross-linking relationship between systems is complex and the number of cables is large, which increases the complexity of the whole airborne system. Requirements for hardware resources of the airborne system are very high, and the contradiction between the high demand for the integrated airborne system and the slow upgrade speed of hardware resources appears. The demand for intelligent airborne systems are also developing. This paper presents a scheme of distributed cloud-edge-terminal intelligent architecture for airborne system, which combines cloud-edge-terminal technology, distributed network control technology, distributed integrated modular avionics system technology, and is reasonably constructed through cloud management platform, edge control platform and terminal platform, and configures high-speed secure real-time network and container software technology. Without increasing the complexity of the whole aircraft, the integration of multi-airborne systems can be improved. At the same time, the architecture can also meet needs of the application of new technologies such as artificial intelligence, information fusion, large data processing and the expansion of new functions. This architecture provides a solution for the future integrated and intelligent development of airborne systems.

Abstract:The software development process encounters several challenges due to the increasingly functional, complex, expensive, and condensed development cycles of civil aircraft avionics systems, including inaccurate requirements, overly coupled architecture design, and difficult tracing process outputs. We propose a solution to the difficult software development issues for civil aircraft avionics systems based on research into digital development, process development, continuous integration, cloud development environments, and other cutting-edge technologies and methods. The research paper demonstrates how the solution for civil aviation software development is used in the process of developing avionics systems software. The findings demonstrate the viability of the complex avionics system software development and management method for civil aircraft proposed in this paper. To increase the effectiveness and caliber of software development, the method has been used in the development of the C919 civil aircraft display system.

Abstract:The existing technologies are difficult to identify the airborne software faults and the corresponding causes, and thus can’t be applied in the development process of the airborne software easily. To resolve the above problems, we proposed the airborne software fault modeling and analysis approach based on the system architecture and operation diagram. First, we proposed the airborne software fault identify approach based on the function failure analysis, which can be used to identify the airborne software faults caused by the interface data, time constraint and so on. Then we construct the fault hierarchy modeling approach based on the static system architecture, the fault logic relationship modeling approach based on the dynamic operation diagram respectively, which can be used for constructing the software fault tree effectively. Then, we proposed the safety requirement analysis approach based on the software requirement and criteria. Finally, we applied these approaches on the airborne brake control software for validation the effectiveness and feasibility. The experimental results show that the proposed airborne fault modeling and analysis approach is feasible and consistent with the standard requirement, and is suitable for constructing the V&V loop of the airborne software fault analysis and validation

Abstract:Due to the highly integrated avionics systems of civil aircraft, which directly contribute to an exponential rise in the size of airborne safety-critical software, and the duality in the transfer of requirements at each level of the avionics system software, a Safety SysML consistency verifier is developed on the basis of research into safety state machines.This paper firstly introduces the syntax of Safety_SysML, followed by the design of the Safety_SysML consistency verifier, including static data detection and dynamic data detection. Finally, test cases are designed for unit and integration test of the core algorithm and system. Based on the model consistency requirements and influencing factors such as migration conditions, functional tests are designed and executed through error inference and boundaries to find defects in the verifier. The above test results and aircraft examples are used to supplement the validator to verify the correctness of the model consistency and avoid uncertain behaviour of the system. The result shows that this method can effectively identify the problem of duality in avionics system software, which is important for improving the safety and reliability of avionics software.

Abstract:With the increasing use of software tools in the process of developing and verifying airborne software to meet DO-178C, In order to ensure its airworthiness and safety, DO-178C uses DO-330 as a guide for software tool qualification process. At present, COTS tools can not meet the requirements of specific project development and verification. The evaluation tool qualification level, life cycle process and objective of tool qualification in DO-330 are used as the guidance basis. The main concerns and difficulties in the process of DO-330 engineering practice are analysed. Combined with the actual project, the qualification process of self-developed tool to meet the requirements of DO-330 is given. The research results show that the self-developed tool qualification of Tool Qualification Level 5 (TQL-5) proposed in this paper has engineering feasibility and has made substantial progress. It provides reference and guidance for organizations that cannot use COTS to meet specific project requirements and need to perform software tool qualification according to DO-330 requirements.